Vehicle with aerial and ground mobility

ABSTRACT

A combination rotor and wheel assembly for an unmanned vehicle with ground and aerial mobility has a rotor arm adapted to be attached at an inner end thereof to a vehicle body. A rotor is rotatably connected to an outer end of the rotor arm about a rotor axis, and a rotor drive mounted on the rotor arm rotates the rotor such that the rotor exerts an upward lift force on the rotor arm. An open spoked wheel is rotatably connected about the rotor axis independent of the rotor The diameter of the wheel is greater than that of the rotor, and a bottom edge of the wheel is below the rotor. A wheel drive rotates the wheel. Vehicles can have various numbers and orientations of the rotor and wheel assembly to provide aerial and ground mobility.

This invention is in the field of unmanned vehicles (UMV) and inparticular a UMV that has both the capabilities of an unmanned aerialvehicle (UAV) and of an unmanned ground vehicle (UGV), and thus can bothfly and roll along the ground.

BACKGROUND

Remote controlled unmanned vehicles are well known for use in militaryand police surveillance, bomb disposal, disaster investigation, and thelike. Most commonly these UMVs are unmanned ground vehicles (UGV) whichhave the ability to travel only along the ground, or unmanned aerialvehicles (UAV) which have the ability to travel only in the air.

Aerial vehicles, commonly electric battery powered hovering vehicleswith spinning rotors for lift and propulsion, have the ability to accesselevated areas like windows and roof tops and provide a wide range ofobservation, but have a limited operating time due to the high energyrequirements of flight and the weight of batteries. Such an aerialvehicle is disclosed for example in U.S. Pat. No. 7,510,142 to Johnson.

Ground vehicles have a much longer operating time but have difficultiesaccessing elevated areas, and maneuvering over stairs and likeobstacles. Such a ground vehicle is disclosed for example in U.S. Pat.No. 6,144,180 to Chen et al.

Due to the limitations of such a single travel mode, UMVs have beendeveloped which have the capability to travel both in the air and alongthe ground. For example U.S. Pat. No. 8,205,820 to Goossen et al.discloses an aerodynamic flying assembly comprising an unmanned aerialvehicle integrated with an unmanned ground vehicle A power unit andcontrols are shared by the unmanned aerial vehicle and the unmannedground vehicle, and a disengagement mechanism separates the unmannedground vehicle from the unmanned aerial vehicle for ground operations.

U.S. Pat. No. 6,588,701 to Yavnai discloses a remotely-controlledunmanned mobile device that is operable in either of two modes. Thedevice has a rotor assembly that allows it to vertically take off andland, to fly to a selected site and then hover. The device walks on legsthat extend from the device for a ground mode of operation, and retractfor a flying mode of operation.

U.S. Pat. No. 7,959,104 to Kuntz discloses a combination UAV/UGVcomprising a vehicle body with front and rear rotors mounted on eachside of the body about corresponding rotational axes. Each rotor has anannular covering attached to the tips of the rotor blades such that thecovering essentially forms a wheel with the rotor blades acting as thespokes. The rotors are movable from a flying mode, where the rotationalaxes are oriented vertically such that the rotating rotors provide lift,to a ground mode where the rotational axes are oriented horizontally andthe body is supported on the annular covering, and the rotating rotorsact as wheels to move the body along the ground.

A problem with the Kuntz vehicle is that in ground mode, the wheeltreads will often pick up debris which unbalances the rotor/wheelassembly and which can make the vehicle unable to fly. Also the annularcovering increases the mass that must be rotated for flight. Furthersince the annular covering spins with the rotors, any contact with wallsor the like during flight can damage the rotor. Even slight contact canslow the rotor such that control is difficult, and can also upset thebalance of the rotor and adversely affect flying.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an unmanned vehicleapparatus that overcomes problems in the prior art.

In a first embodiment the present invention provides a combination rotorand wheel assembly for an unmanned vehicle with ground and aerialmobility. The assembly comprises a rotor arm adapted to be attached atan inner end thereof to a vehicle body. A rotor is rotatably connectedto an outer end of the rotor arm about a rotor axis, and a rotor drivemounted on the rotor arm is operative to rotate the rotor such that therotor exerts an upward lift force on the rotor arm. An open spoked wheelis rotatably connected to the outer end of the rotor arm about the rotoraxis independent of the rotor A diameter of the wheel is greater than adiameter of the rotor, and a bottom edge of the wheel is below therotor. A wheel drive is mounted on the arm and is operative to rotatethe wheel.

In a second embodiment the present invention provides an unmannedvehicle apparatus comprising a vehicle body, and right and left rotorarms extending from corresponding right and left sides of the vehiclebody. A rotor is rotatably connected to an outer end of each rotor armabout a rotor axis, and a rotor drive is operative to rotate each rotorsuch that each rotor exerts an upward lift force on the correspondingrotor arm. A corresponding open spoked wheel is rotatably connected tothe outer end of each rotor arm about the rotor axis independent of therotor. A diameter of the wheel is greater than a diameter of thecorresponding rotor, and a bottom edge of the wheel is below the rotor,and a wheel drive is operative to rotate the wheels. The right and leftrotor arms are oriented such that the bottom edges of the wheels supportthe vehicle body for movement along the ground, and such that the liftforce generated by rotating the rotors is operative to raise the vehiclebody and wheels above the ground.

The rotor arms of the rotor and wheel assemblies can be pivotallyattached to the body of the vehicle so that the rotational axes of therotors can be moved to a more upright orientation, typically nearvertical, so that substantially all of the lift force exerted by thespinning rotors is directed upward to provide lift for the vehicle.Remote controls operate the wheel drives independently for groundsteering and propulsion, operate the rotor drives to provide aerialsteering and propulsion, and also pivot the arms with respect to thebody to convert the vehicle from a flying to a ground position. Cameraswill typically be mounted on the body to allow for control andobservation.

During flight the wheel is stationary while the rotor spins inside thewheel, such that any debris picked up by the wheels does not affect thebalance of the rotor. The mass that is rotated at high speed for flyingmode is also much reduced compared to the prior art, reducing powerrequirements. The stationary wheel also serves to protect the rotor fromcontact with building walls or like objects during flight.

DESCRIPTION OF THE DRAWINGS

While the invention is claimed in the concluding portions hereof,preferred embodiments are provided in the accompanying detaileddescription which may be best understood in conjunction with theaccompanying diagrams where like parts in each of the several diagramsare labeled with like numbers, and where:

FIG. 1 is a schematic top view of an embodiment of an unmanned vehicleapparatus of the present invention shown in a flying position;

FIG. 2 is a schematic front view of the embodiment of FIG. 1 shown inthe flying position;

FIG. 3 is a schematic front view of the embodiment of FIG. 1 shown inthe ground position;

FIG. 4 is a schematic top view of an embodiment of a rotor and wheelassembly of the present invention, as installed on the embodiment of thevehicle apparatus of FIG. 1;

FIG. 5 is a schematic front view of the embodiment of the rotor andwheel assembly of FIG. 4;

FIG. 6 is a schematic front view of the embodiment of FIG. 1 shown inthe ground position, and illustrating the orientation and relativemagnitudes of the force components exerted by the spinning rotor;

FIGS. 7A and 7B respectively show front and top views of an alternatefixed arm two rotor/wheel embodiment of an unmanned vehicle apparatus ofthe present invention shown in the flying position;

FIGS. 7C and 7D respectively show side and top views of the fixed tworotor/wheel embodiment of FIGS. 7A, 7B shown in the ground position;

FIGS. 8A and 8B respectively show respectively show front and top viewsof an alternate pivoting arm two rotor/wheel embodiment of an unmannedvehicle apparatus of the present invention shown in the flying position;

FIGS. 8C and 8D respectively show side and top views of the pivoting armtwo rotor/wheel embodiment of FIGS. 8A, 8B shown in the ground position;

FIGS. 9A and 9B respectively show respectively show front and top viewsof an alternate pivoting arm three rotor/wheel embodiment of an unmannedvehicle apparatus of the present invention shown in the flying position;

FIGS. 9C and 9D respectively show side and top views of the pivoting armthree rotor/wheel embodiment of FIGS. 9A, 9B shown in the groundposition;

FIGS. 10A and 10B respectively show respectively show front and topviews of an alternate pivoting arm six rotor/wheel embodiment of anunmanned vehicle apparatus of the present invention shown in the flyingposition;

FIGS. 10C and 10D respectively show side and top views of the pivotingarm six rotor/wheel embodiment of FIGS. 10A, 10B shown in the groundposition;

FIG. 11 is a schematic top view of an alternate embodiment of a rotorand wheel assembly of the present invention;

FIG. 12 is a schematic front view of the embodiment of the rotor andwheel assembly of FIG. 11;

FIGS. 13A-13C schematically illustrate front views of an alternateembodiment of an unmanned vehicle apparatus of the present inventionshown in the flying, ground, and stored positions;

FIGS. 14A-14C schematically illustrate front views of another alternateembodiment of an unmanned vehicle apparatus of the present inventionshown in the flying, ground, and stored positions.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIGS. 1-3 schematically illustrate an embodiment of an unmanned vehicleapparatus 1 of the present invention. The apparatus 1 comprises avehicle body 3 and right and left rotor and wheel assemblies 4R, 4Lextending from corresponding right and left sides of the vehicle body 3.

Each rotor and wheel assembly 4, as schematically illustrated in FIGS. 4and 5, comprises a rotor arm 5 adapted to be attached at an inner endthereof to the vehicle body 3, and a rotor 7 rotatably connected to anouter end of the rotor arm 5 about a rotor axis RA, and a rotor drive ismounted on the rotor arm operative to rotate the rotor 7 such that therotor exerts an upward lift force LF on the rotor arm 5 in the directionof the rotational axis RA. In the illustrated apparatus 1 the rotordrive is provided by a rotor motor 9 mounted on the rotor arm 5 andconnected directly to the rotor 7. An open spoked wheel 11 is rotatablyconnected to the outer end of the rotor arm 5 about the rotor axis RAindependent of the rotor 7. The diameter of the wheel 11 is greater thanthe diameter of the rotor 7, and a bottom edge 13 of the wheel 11 isbelow the rotor 7. Thus the rotor 7 rotates inside the wheel 11, andabove the bottom of the wheel 11 such that the rotor blades areprotected from contact with walls or the like when flying. The openspoked structure of the wheel 11 allows air to flow freely to the rotor7 to provide lift when flying. A wheel drive is mounted on the arm andoperative to rotate the wheel 11.

In the illustrated assembly 4, the wheel 11 comprises an annular rim 15connected by spokes 17 to a hub 19 that is rotatably attached to the endof the arm 5, and an annular tread member 21 is connected to the rim 15below the rim and concentric with the rim such that the bottom edge 13of the wheel is provided by the tread member 21.

Also in the illustrated assembly 4, the rims 15 on front wheels 11RF,11LF on the front rotor and wheel assemblies 4RF, 4LF define gear teeth23 and the wheel drive is provided by a wheel motor 25 mounted on eachcorresponding front rotor arm 5RF, 5LF with a sprocket 27 mounted on themotor shaft that is operative to engage the gear teeth 23 to rotate thefront wheels 11RF, 11LF.

The rotor 7 thus rotates in a protected plane just below the rim 15 andabove the tread member 21. The diameter of the rotor 7 is about the sameas the inside diameter of the tread member 21.

It is contemplated that the combination rotor and wheel assembly 4 canbe used in various ways to provide an unmanned vehicle with ground andaerial mobility, for example a vehicle with only two rotor and wheelassemblies, one on the right and one on the left side of the body, couldconceivably operate satisfactorily. Such alternative embodiments arediscussed below.

The illustrated apparatus 1 however, for increased stability, has fourrotor and wheel assemblies 4 illustrated as front and rear right rotorand wheel assemblies 4RF, 4RR and front and rear left rotor and wheelassemblies 4LF, 4LR. To provide ground steering and propulsion in theillustrated four wheeled apparatus 1, the right wheel 11RF on the rightside and the left wheel 11LF on the left side are driven at variablespeeds independently of each other.

The right and left front and rear rotor and wheel assemblies 4RF, 4RR,4LF, 4LR are oriented such that the bottom edges 13 of the wheels 11support the vehicle body 3 for movement along the ground, and such thatrotating or spinning the rotors 7 provides a lift force operative toraise the vehicle body 3 and attached rotor and wheel assemblies 4 abovethe ground. In the illustrated apparatus 1 a remote rotor control 29 isoperative to independently vary the rotational speed of the rotor motors9 to provide flight control, and a remote wheel control 31 is operativeto independently vary the rotational speed of the wheel motors 25 toprovide ground propulsion and steering control.

Also, as seen in the top view of FIG. 1, only the front right and frontleft rotor and wheel assemblies 4RF, 4LF are equipped with a wheel motor25 while the rear right and left rotor and wheel assemblies 4RR, 4LR aresimply allowed to roll freely, thus providing a two wheel drive groundvehicle.

FIGS. 3 and 6 schematically illustrate a front view of the apparatus 1showing the bottom edges of the wheels 13 resting on the ground, and therotor axes RA tilted at an angle N of about 40 degrees down fromvertical. Operating the wheel motors 25 will move the apparatus 1 alongthe ground, and varying the speed of the wheel 11 on one side relativeto that on the other side provides steering control.

As illustrated in FIG. 6, spinning the rotors 7 when in this orientationwill create an upward lift force LF in the direction of the tilted rotoraxis RA, and result in an actual upward lift component of LF which isonly about 77% of the force LF generated by the rotor 7. It iscontemplated that the rotor and wheel assemblies 4 could be fixed atsome similar angle where the upward lift component of LF′ is sufficientto lift the apparatus 1 off the ground, and the wheels 11 are orientedsuitably for movement along the ground. Such an arrangement would befairly simple to make, however a significant proportion of the liftforce LF generated by the rotors 7 will be wasted.

To avoid this waste of energy, in the illustrated apparatus 1 the arms 5of each of the rotor and wheel assemblies 4 are pivotally mounted to thebody 3, and an arm actuator 33 is operative to pivot the arms 5 of therotor and wheel assemblies 4 from the flying position shown in FIG. 2,where the rotor axes RA are in an upright orientation, to the groundposition shown in FIG. 3 where the rotor axes RA are in a lateralorientation.

It is contemplated that when in the flying position the rotor axes RAwill be oriented within about 10 degrees of vertical. With an angle of10 degrees, the actual upward lift component of LF will be about 98% ofthe force LF generated by the rotor 7, significantly increasing the liftcapabilities compared to an angle of 40 degrees. When in the groundposition, the rotational axes RA could be tilted down to 90 degrees fromvertical, such that the rotational axes RA are horizontal and the wheelsare oriented vertically as in a conventional vehicle. FIGS. 13C and 14Cdescribed below show such an orientation which is convenient for storageand portability of the apparatus 1. It is contemplated however that suchan orientation is not required for satisfactory ground operations, andthat the mechanism of the arm actuator 33 can be simplified by reducingthe downward tilt to between about 30 degrees and about 50 degreesdownward from vertical when in the ground position, and still besatisfactory. The wider stance between the contact points of the wheelsand ground on right and left sides when the arms are oriented betweenabout 30 degrees and about 50 degrees also increases the stability ofthe apparatus in the ground position.

To further simplify the mechanism of the arm actuator 33 the front andrear right rotor arms 5RF, 5RR are mounted to a right arm plate 35R andoriented such that front and rear right rotor axes RARE. RARR aresubstantially parallel, corresponding front and rear right wheels 11RF,11RR are aligned and oriented to roll in a ground operating traveldirection T, and the right arm plate 35R is pivotally attached to alower portion of the vehicle body 3 about a plate pivot axis PPAoriented substantially in alignment with the ground operating traveldirection T.

Similarly the front and rear left rotor arms 5LF, SLR are mounted to aleft arm plate 35L and oriented such that front and rear left rotor axesRALF, RALR are substantially parallel, corresponding front and rear leftwheels 11LF, 11LR are aligned and oriented to roll in the groundoperating travel direction T, and the left arm plate 35L is pivotallyattached to the vehicle body 3 about the same plate pivot axis PPA. Inthe illustrated apparatus 1, the right and left plate pivot axes PPA forthe corresponding right and left arm plates 35R, 35L coincide, howeverit is contemplated that they could be separated by a distance, as shownfor example in FIG. 14A described below.

In the illustrated apparatus 1, the arm actuator 33 is operative topivot both the right and left arm plates 35R, 35L simultaneously fromthe flying position shown in FIG. 2 where the rotor axes RA are in anupright orientation, to the ground position shown in FIG. 3 where therotor axes RA are in a lateral orientation. The arms 5 are thuscontrolled simply by a single mechanism, again operated by a remote armcontrol 37.

Further embodiments of an unmanned vehicle apparatus of the presentinvention are schematically illustrated in FIGS. 7A-10D. FIGS. 7A-7Dschematically illustrate a vehicle apparatus 101 with two fixed rotorand wheel assemblies 104, with arms 105 fixed to right and left sides ofthe body 103. In the flying position illustrated in FIGS. 7A (front) and7B (top), the spinning rotors 107 create a lift force LF and the lateralorientation of the rotational axes RA results in an actual upward liftcomponent LF′ which will be calculated to be sufficient to lift theapparatus 101 such that the tail end 141 of the body 103 hangs down. Inthe ground position illustrated in FIGS. 7C (side) and 7D (top), thewheels 111 are oriented for ground travel and the tail end 141 drags onthe ground on a skid surface, or a small wheel could be provided as welldepending on the application.

FIGS. 8A-8D schematically illustrate a vehicle apparatus 201 with twopivoting rotor and wheel assemblies 204, with arms 205 pivotallyattached to right and left sides of the body 203. In the flying positionillustrated in FIGS. 8A (front) and 8B (top), the spinning rotors 207create a lift force LF and the rotational axes RA are orientedsubstantially vertically so that all the lift force LF exerts an upwardforce to lift the apparatus 201 into the air with the tail end 241 ofthe body 203 hanging down. In the ground position illustrated in FIGS.8C (side) and 8D (top), the wheels 211 are pivoted to an orientation forground travel and the tail end 241 again drags on the ground.

FIGS. 9A-9D schematically illustrate a vehicle apparatus 301 with threepivoting rotor and wheel assemblies 304, with arms 305 pivotallyattached to the body 303 and substantially equally spaced around thebody 303. In the flying position illustrated in FIGS. 9A (front) and 9B(top), the spinning rotors 307 create a lift force LF and the rotationalaxes RA are oriented substantially vertically so that all the lift forceLF exerts an upward force to lift the apparatus 301 into the air. In theground position illustrated in FIGS. 9C (side) and 9D (top), the wheels311 are pivoted to an orientation for ground travel.

FIGS. 10A-10D schematically illustrate a vehicle apparatus 401 with sixpivoting rotor and wheel assemblies 404, with arms 405 pivotallyattached to the body 403 and substantially equally spaced around thebody 403. In the flying position illustrated in FIGS. 10A (front) and10B (top), the spinning rotors 407 create a lift force LF and therotational axes RA are oriented substantially vertically so that all thelift force LF exerts an upward force to lift the apparatus 401 into theair. In the ground position illustrated in FIGS. 10C (side) and 10D(top), the wheels 411 are pivoted to an orientation for ground travel.

Wheels on the right and left sides would be rotated at variable speedsindependently of each other to provide directional steering control forground travel. Other numbers and orientations of rotor and wheelassemblies are contemplated and as well, additional fixed conventionalrotors could be attached to the body where increased lift was desired.

The rotor and wheel assemblies are attached in selected numbers andorientations to suit the particular application being pursued, eitherfixed or pivotally, to a vehicle body to provide vehicles, such as theunmanned vehicle apparatuses 1, 101, 201, 301, 401 described above, thathave both aerial and ground mobility.

It is contemplated that various other wheel mechanisms could be used aswell. For example FIGS. 11 and 12 schematically illustrate an alternateembodiment of a rotor and wheel assembly 504 of the present invention.In the rotor and wheel assembly 504 the wheel 511 comprises an annularfixed rim 515 connected by spokes 517 to a hub 519 that is fixed to thearm 505 at the rotor axis RA, instead of being rotatably attached at therotor axis as in the rotor and wheel assembly 4 described above.Instead, an annular tread member 521 is rotatable on the outer surfaceof the fixed rim 515 and only the tread member rotates about the rotoraxis. The bottom edge of the wheel 511 is provided by the tread member521.

The rotor drive is provided by a rotor motor 509 mounted on the rotorarm 505 and connected directly to the rotor 507 which rotates inside thewheel 511, and above the bottom of the wheel 111 such that the rotorblades are protected from contact with walls or the like when flying.The open spoked structure of the wheel 511 allows air to flow freely tothe rotor 507 to provide lift when flying. The fixed rim 515 definesgear teeth 523 and the wheel drive is provided by a wheel motor 525mounted on rotor arm 505 with a sprocket 527 mounted on the motor shaftthat is operative to engage the gear teeth 523 to rotate the treadmember 521 on the fixed rim 515.

FIGS. 13A-13C schematically illustrate an alternate apparatus 601 thatis movable to a stored position where the rotor arms 605 of the rightand left rotor and wheel assemblies 604 are movable from the flyingposition of FIG. 13A to the ground position of FIG. 13B to a storedposition shown in FIG. 13C where the rotor axes RA of the rotor andwheel assemblies 604 are oriented substantially horizontally.

In the apparatus 601 of FIGS. 13A-13C the right and left arms 605 pivotabout a common pivot axis PA. FIGS. 14A-14C schematically illustrate afurther alternate apparatus 701 that is movable to a stored positionwhere the rotor arms 705 of the right and left rotor and wheelassemblies 704 pivot about separated pivot axes RPA, LPA and are againmovable from the flying position of FIG. 14A to the ground position ofFIG. 14B to the stored position shown in FIG. 14C where the rotor axesRA are oriented substantially horizontally.

While it may be possible to configure the same arm actuator that movesthe arms from the flying position to the ground position to also movethe arms to the stored position, it may be simpler to simply providesome manual release to move the arms to the stored position, since thisneed only be done when the apparatus is stationary. It may also bedesired in some applications to configure an unmanned vehicle to operateon the ground while the rotor axes are in the horizontal storedposition.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous changes and modifications willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all such suitable changes or modificationsin structure or operation which may be resorted to are intended to fallwithin the scope of the claimed invention.

What is claimed is:
 1. A combination rotor and wheel assembly for anunmanned vehicle with ground and aerial mobility, the assemblycomprising: a rotor arm adapted to be attached at an inner end thereofto a vehicle body; a rotor rotatably connected to an outer end of therotor arm about a rotor axis, and a rotor drive mounted on the rotor armoperative to rotate the rotor such that the rotor exerts an upward liftforce on the rotor arm; an open spoked wheel rotatably connected to theouter end of the rotor arm about the rotor axis independent of therotor, wherein a diameter of the wheel is greater than a diameter of therotor, and wherein a bottom edge of the wheel is below the rotor; awheel drive mounted on the arm and operative to rotate the wheel.
 2. Theassembly of claim 1 wherein the arm is adapted to be pivotally attachedto the vehicle body about a substantially horizontal arm axis.
 3. Theassembly of claim 1 wherein the rotor drive comprises a rotor motormounted on the rotor arm and connected to the rotor and comprising arotor control operative to vary a rotational speed of the rotor motor.4. The assembly of claim 1 wherein the wheel comprises an annular rimconnected by spokes to a hub rotatably mounted to the arm about therotor axis, and an annular tread member connected to the rim below therim and concentric with the rim such that the bottom edge of the wheelis provided by the tread member.
 5. The assembly of claim 4 wherein therotor rotates in a plane below the rim and above the tread member. 6.The assembly of claim 4 wherein the rim defines gear teeth and whereinthe wheel drive comprises a wheel motor mounted on the rotor arm andoperative to engage the gear teeth to rotate the wheel.
 7. The assemblyof claim 1 wherein the wheel comprises an annular fixed rim connected byspokes to a hub fixed to the arm at the rotor axis, and an annular treadmember rotatable on an outer surface of the fixed rim, and wherein thebottom edge of the wheel is provided by the tread member.
 8. An unmannedvehicle apparatus comprising: a vehicle body; right and left rotor andwheel assemblies according to claim 1 attached to and extending fromcorresponding right and left sides of the vehicle body; wherein theright and left rotor and wheel assemblies are oriented such that thebottom edges of the wheels support the vehicle body for movement alongthe ground, and such that the upward lift force generated by rotatingthe rotors is operative to raise the vehicle body and wheels above theground.
 9. The apparatus of claim 8 wherein the rotor arms of the rightand left rotor and wheel assemblies are pivotally mounted to the bodyabout substantially horizontal arm pivot axes, and comprising an armactuator operative to tilt the right and left rotor arms such that therotor axis RA moves from a flying position, where the rotor axes are inan upright orientation, outward and downward toward a laterally orientedground position.
 10. The apparatus of claim 9 wherein the rotor axes areoriented within about 10 degrees of vertical when in the flyingposition.
 11. The apparatus of claim 10 wherein the rotor axes areoriented between about 30 degrees and about 50 degrees downward fromvertical when in the ground position.
 12. The apparatus of claim 9wherein the rotor arms of the right and left rotor and wheel assembliesare movable to a stored position wherein the rotor axes thereof areoriented substantially horizontally.
 13. The apparatus of claim 8comprising front and rear right and left rotor and wheel assembliesmounted to the vehicle body.
 14. The apparatus of claim 13 wherein thefront and rear right rotor and wheel assemblies are mounted to a rightarm plate and oriented such that front and rear right rotor axes aresubstantially parallel, corresponding front and rear right wheels arealigned and oriented to roll in a ground operating travel direction, andwherein the right arm plate is pivotally attached to a lower portion ofthe vehicle body about a plate pivot axis oriented substantially inalignment with the ground operating travel direction.
 15. The apparatusof claim 14 wherein the front and rear left rotor and wheel assembliesare mounted to a left arm plate and oriented such that front and rearleft rotor axes are substantially parallel, corresponding front and rearleft wheels are aligned and oriented to roll in the ground operatingtravel direction, and wherein the left arm plate is pivotally attachedto the vehicle body about the plate pivot axis.
 16. The apparatus ofclaim 15 comprising an arm actuator operative to tilt the right and leftarm plates such that the rotor axes move from a flying position, wherethe rotor axes are in an upright orientation, outward and downwardtoward a laterally oriented ground position.
 17. An unmanned vehicleapparatus comprising: a vehicle body; right and left rotor armsextending from corresponding right and left sides of the vehicle body; arotor rotatably connected to an outer end of each rotor arm about arotor axis, and a rotor drive operative to rotate each rotor such thateach rotor exerts an upward lift force on the corresponding rotor arm; acorresponding open spoked wheel rotatably connected to the outer end ofeach rotor arm about the rotor axis independent of the rotor, wherein adiameter of the wheel is greater than a diameter of the correspondingrotor, and wherein a bottom edge of the wheel is below the rotor; awheel drive operative to rotate the wheels; wherein the right and leftrotor arms are oriented such that the bottom edges of the wheels supportthe vehicle body for movement along the ground, and such that the liftforce generated by rotating the rotors is operative to raise the vehiclebody and wheels above the ground.
 18. The apparatus of claim 17 whereinthe right and left rotor arms are pivotally mounted to the body about asubstantially horizontal arm pivot axis, and comprising an arm actuatoroperative to pivot the right and left rotor arms from a flying positionwhere the rotor axes are in an upright orientation, to a ground positionwhere the rotor axes are in a lateral orientation.
 19. The apparatus ofclaim 18 wherein the rotor axes are oriented within about 10 degrees ofvertical when in the flying position.
 20. The apparatus of claim 19wherein the rotor axes are oriented between about 30 degrees and about50 degrees downward from vertical when in the ground position.
 21. Theapparatus of claim 17 wherein at least one rotor drive comprises a rotormotor mounted on the corresponding rotor arm and connected to thecorresponding rotor and comprising a rotor control operative to vary arotational speed of the rotor motor.
 22. The apparatus of claim 17wherein at least one wheel comprises an annular rim connected by spokesto a hub, and an annular tread member connected to the rim below the rimand concentric with the rim such that the bottom edge of the at leastone wheel is provided by the tread member.
 23. The apparatus of claim 22wherein the rim defines gear teeth and wherein the wheel drive operativeto drive the at least one wheel comprises a wheel motor mounted on therotor arm and operative to engage the gear teeth to rotate the at leastone wheel.
 24. The apparatus of claim 17 comprising front and rear rightand left rotor arms mounted to the vehicle body, with correspondingfront and rear right and left rotors and wheels mounted thereon aboutcorresponding rotor axes, and wherein the wheel drive is operative torotate at least one right wheel and at least one left wheel.
 75. Theapparatus of claim 24 wherein the front and rear right rotor arms aremounted to a right arm plate and oriented such that front and rear rightrotor axes are substantially parallel, corresponding front and rearright wheels are aligned and oriented to roll in a ground operatingtravel direction, and wherein the right arm plate is pivotally attachedto a lower portion of the vehicle body about a right plate pivot axisoriented substantially in alignment with the ground operating traveldirection.
 26. The apparatus of claim 25 wherein the front and rear leftrotor arms are mounted to a left arm plate and oriented such that frontand rear left rotor axes are substantially parallel, corresponding frontand rear left wheels are aligned and oriented to roll in the groundoperating travel direction, and wherein the left arm plate is pivotallyattached to the vehicle body about a left plate pivot axis orientedsubstantially in alignment with the ground operating travel direction.27. The apparatus of claim 26 comprising an arm actuator operative topivot the right and left arm plates from a flying position where therotor axes are in an upright orientation, to a ground position where therotor axes are in a lateral orientation.
 28. The apparatus of claim 27wherein the rotor axes are oriented within about 10 degrees of verticalwhen in the flying position, and the rotor axes are oriented betweenabout 30 degrees and about 50 degrees downward from vertical when in theground position.
 29. The apparatus of claim 28 wherein the wheel drivecomprises a right wheel drive operative to rotate one of the front andrear right wheels and a left wheel drive operative to rotate one of thefront and rear left wheels, and a wheel drive control operative toindependently vary a drive speed of the right and left wheel drives. 30.The apparatus of claim 26 wherein the right and left plate pivot axescoincide.
 31. The apparatus of claim 26 wherein the right and left armplates are movable to a stored position where all the rotor axes areoriented substantially horizontally.